There is conventionally known a configuration in which power and heat are generated by a fuel cell using a fuel gas and hot water obtained by heating tap water with the heat is stored in a hot water tank to be supplied to a bath and so on (e.g., see patent literature PLT 1 set forth below). For example, to fairly allocate, to each unit of an apartment, cost burden of the fuel gas used by the fuel cell installed in an apartment, it is necessary to separate an amount of the fuel gas used by the fuel cell into an amount used for power generation and an amount used for water heating.